Since the events of Sep. 11, 2001, the world, and in particular the US, has become more aware of the need to monitor and detect terror, chemical, biological, and explosive threats. Typically, detection has either been a manual process, or has required a substantial installation process. For the manual process, people with detectors are positioned or rove in high risk areas to monitor for target threat agents. These agents are typically released or accompany known chemical, biological, or explosive threats. Each person monitors one or more manually-positioned detector, and reports when a threat is detected. However, such a manual detection process is highly intrusive, as it requires the presence of security and monitoring personnel at the risk site, and, it is not possible to fully protect a large area over extended periods due to staffing limitations. Also, some sensors may be checked only periodically as the security person makes their rounds. Since reaction time is critical in many threat situations, such a delay can have severe consequences.
The more permanently installed detection systems offer the benefit of being less noticeable in the risk area, but typically require the installation of a supporting power and data infrastructure to support a set of detectors. Also, since each detector is expensive, the overall cost of protecting an area is quite high, and limits the density of protection in all but the most critical areas. Unfortunately, in today's world, almost every building, event, and transportation system is a potential target of attack. With the cost and difficulty of installing these permanent systems, very few potential targets are actually being monitored. For example, it is generally agreed that security, especially security against biological, chemical, and explosive threats, needs to be improved for shipping and air cargo facilitates and containers, truck trailers, airport terminals, border check points, and other high value/high traffic locations. Also, the permanently installed systems are ineffective or uneconomical for temporary events. For example, an important dignitary may be making a one-hour speech at a hotel. Although the hotel may benefit from an installed detection system, it is not economically feasible to install a full threat detection system to support threat detection for just one speech. Therefore, such events are typically monitored by security personnel, which detracts from and interferes with the event. And, as described above, human monitoring may provide a threat response that is too slow to be effective.
Although terrorist threats are receiving much attention, other threats also need to be addressed. For example, manufacturing threats, such as gas leaks, biological agent release, and chemical spills pose a threat to workers as well as to the surrounding area. In another example, environmental threats, such as air pollution, water contamination, and the use of illegal pesticides and herbicides present vast areas that are currently difficult to monitor. In a final example, medical maladies and infections need to be identified prior to effective containment or treatment. Often, outbreaks occur in relatively remote areas, such as in rural areas of developing countries. Due to the cost of the medical assaying devices, and the sophistication needed to operate them, such devices are not readily available in these areas.